Critical Ultrasound Journal最新文献

In the unconscious patient, there is a diagnostic void between the neurologic physical exam, and more invasive, costly and potentially harmful investigations. Transcranial color-coded sonography and two-dimensional transcranial Doppler imaging of the brain have the potential to be a middle ground to bridge this gap for certain diagnoses. With the increasing availability of point-of-care ultrasound devices, coupled with the need for rapid diagnosis of deteriorating neurologic patients, intensivists may be trained to perform point-of-care transcranial Doppler at the bedside. The feasibility and value of this technique in the intensive care unit to help rule-in specific intra-cranial pathologies will form the focus of this article. The proposed scope for point-of-care transcranial Doppler for the intensivist will be put forth and illustrated using four representative cases: presence of midline shift, vasospasm, raised intra-cranial pressure, and progression of cerebral circulatory arrest. We will review the technical details, including methods of image acquisition and interpretation. Common pitfalls and limitations of point-of-care transcranial Doppler will also be reviewed, as they must be understood for accurate diagnoses during interpretation, as well as the drawbacks and inadequacies of the modality in general.

Background: Conventional echocardiographic technique for assessment of volume status and cardiac contractility utilizes left ventricular end-diastolic area (LVEDA) and fractional area of change (FAC), respectively. Our goal was to find a technically reliable yet faster technique to evaluate volume status and contractility by measuring left ventricular end-diastolic diameter (LVEDD) and fractional shortening (FS) in a cohort of mechanically ventilated trauma and burn patients using hemodynamic transesophageal echocardiographic (hTEE) monitoring.

Methods: Retrospective chart review performed at trauma/burn intensive care unit (TBICU). Data on 88 mechanically ventilated surgical intensive care patients cared for between July 2013 and July 2015 were reviewed. Initial measurements of LVEDA, left ventricular end-systolic area (LVESA) and FAC were collected. Post-processing left ventricular end-systolic (LVESD) and end-diastolic diameters (LVEDD) were measured and fractional shortening (FS) was calculated. Two orthogonal measurements of LV diameter were obtained in transverse (Tr) and posteroanterior (PA) orientation.

Results: There was a significant correlation between transverse and posteroanterior left ventricular diameter measurements in both systole and diastole. In systole, r = 0.92, p < 0.01 for LVESD-Tr (mean 23.47 mm, SD ± 6.77) and LVESD-PA (mean 24.84 mm, SD = 8.23). In diastole, r = 0.80, p < 0.01 for LVEDD-Tr (mean 37.60 mm, SD ± 6.45), and LVEDD-PA diameters (mean 42.24 mm, SD ± 7.97). Left ventricular area (LVEDA) also significantly correlated with left ventricular diameter LVEDD-Tr (r = 0.84, p < 0.01) and LVEDD-PA (r = 0.90, p < 0.01). Both transverse and PA measurements of fractional shortening were significantly (p < 0.0001) and similarly correlated with systolic function as measured by FAC. Bland-Altman analyses also indicated that the assessment of fractional shortening using left ventricular posteroanterior diameter measurement shows agreement with FAC.

Conclusions: Left ventricular diameter measurements are a reliable and technically feasible alternative to left ventricular area measurements in the assessment of cardiac filling and systolic function.

Ultrasound (US) performed at the point of care has found fertile ground in perioperative medicine. In the hands of anesthesiologists, transesophageal echocardiography (TEE) has become established as a powerful diagnostic and monitoring tool in the perioperative care of cardiac and non-cardiac patients. A number of point-of-care US (POCUS) applications are relevant to perioperative care, including airway, cardiac, lung and gastric US. Although guidelines exist to define the scope of practice for basic and advanced TEE, there remains a lack of such guidelines for perioperative point-of-care ultrasound (POCUS), despite a number of recent calls for action in the academic anesthesia community. POCUS training has been integrated into anesthesia residency curricula in Canada and the United States of America (USA). However, a nation-wide curriculum is still lacking. Many limitations to the development of perioperative POCUS curricula exist, including the need to define the scope of practice and design integrated longitudinal learning approaches. The main anesthesiologist societies in both the USA and Canada are promoting the development of guidelines and have introduced POCUS courses into their national conferences. Although bedside US imaging has been integrated into the curricula of many medical schools in North America, the need for specific national guidelines for the training and practice of POCUS in the perioperative setting by anesthesiologists is crucial to the further development of POCUS in perioperative medicine.

Recently published study of Ma et al. evaluates two relatively novel measures of fluid responsiveness, carotid blood flow and corrected carotid flow time (ccFT). Both measures have been recently quoted as possibly useful, technically simple, and noninvasive dynamic tools in predicting fluid responsiveness. Recently, more research interest has been focused on ccFT and, intrigued by the data presented in this study, we discuss here the impact of the data presented in the paper of Ma et al. to the significance of this metric as a potential tool in the assessment of fluid responsiveness.

Background: Development of hydrocephalus can occur after subarachnoid hemorrhage (SAH). Typically, it is diagnosed with computed tomography, CT, scan. However, transcranial sonography (TCS) can be used particularly in patients with craniotomy which removes the acoustic interference of the skull and allows a closer up visualization of brain structures through the skin.

Case presentation: We report a 73-year-old woman who was hospitalized for SAH and developed acute hydrocephalus requiring an external ventricular drain (EVD). In this patient, detection and monitoring of hydrocephalus was done and monitored with a small pocket-sized TCS device. Nine days after surgery, weaning of the EVD was attempted. Prior to EVD closure and removal, TCS showed a measurement of the 3rd ventricle at around 1.16 cm. On the third day, the patient deteriorated clinically and the TCS showed a dilated 3rd ventricle measuring 1.37 cm which correlated well with computed tomography and with clinical signs of active hydrocephalus as both her sensorium and communication were affected. Subsequently following EVD re-installation, on the next day, TCS showed that the 3rd ventricle dimension was reduced to 0.99 cm and the following day it went down to 0.69 cm.

Conclusions: Patients with SAH and in particular those with a craniotomy can be monitored easily at the bedside with hand-held TCS for the development and monitoring of hydrocephalus.